Molding material and process of making the same.



a novel, cheap and efl'ective moldin amine r. a. moor, or wrnxmsn une, r nnnsrnvanra, nssrenoa "r0 wns'rme-nousn nnncrnrc .an-n nannrncrvamgaeconranr n conronarron or, rnnnsrnvnme.

nonnme Manna Ito Drawing.

ToaZZ whom it may concern:

Be it known that 1, JAMES P. A. McCoy, a subject of the King of Great Britain, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvama, have invented a new and useful Improvement in Molding Materials and Processes of Making the Same, of which the following 1s a s ecification. v A

My invention relates to molding materials and processes of making them, and it has special reference to the manufacture of molding materials suitable for use as electric insulation. i

The object of my invention is to provide ma,- terial that can be readily molded without the application of heat or of expensive solvents, and which, when molded, is of high insulating eficiency.

My process is based upon the fact that certain gums and resins, such as shellac, copal and the synthetic resins of the bakelite type, are soluble in dilute alkaline solutions, from which they may be precipitated by means of tannic acid, alkali-metal tannate being simultaneously formed and thrown down. The tannate does not render the gum .or resin soluble, as free alkali would do, but forms with the gum or resin a plastic mass which is insoluble in water and which can be readily molded in the cold to form hard and durable articles of high dielectric strength.

In carrying out one example of my process, I proceed by dissolving shellac in a weak alkaline solution, such as a 5% solution or borax, sodium hydroxid or potassium hydroxid. I then add to the resulting solution sufiicient concentrated tannic acid to precipitate the shellac and also to throw down the alkali metal as an alkali-metal tannate. The precipitate, consisting of mixed shellac and alkali-metal tannate, is then filtered out of the liquid, washed and dried, forming my novel molding material. This material may be handled in any well known or convenient way for the preparation of molded insulation or other molded articles, either. with or without the addition of the usual inertfillers, such as ground asbestos'or wood flour, and it is to be particularly noted that it is capable of being readily molded without the application of heat. If

desired, fillers may be mixed with the alka- S peoiflcation-ofbette Eato'nt iv Panm mtgedl may 22, 1911?, Application filed .r'ui a, 1 9a. hernia-cement.

cipitate the adhesive and the tannate from the same solution, because of the intimate mlxture of the two substances that is thus produced, and because of the inconvenience that attends the grinding of shellac and other solid gums.

1111 the subjoined claims, the expression varnish adhesive is to be understood as a generic term, includin all gums, resins, gum-resins and synthetic resins which can be used as binders in molding plastic substances.

When shellac is the gum employed, it may be used in any of its ordinary commercial forms, and any of the soluble tannic acids may likewise be employed. It is to be understood that my invention is not restricted to the use of any particular variety of alkalisoluble adhesive substance or to any specific tannin, but is limited on y by the scope of the appended claims.

I claim as my invention:

1. A composition capable of being molded containing a varnish adhesive precipitated in admixture with a metallic tannate.

2. A composition capable of being molded containing a varnish adhesive and an alkalimetal tannate.

3. A composition capable of being molded and comprising an intimate mixture of a single solution a mixture of a varnish adhesive and a metallic tannate.

9. A process of making plastic compositions that comprises dissolving a varnish adhesive in an alkaline liquid and adding tannic acid to the resulting solution.

10. A process of making plastic compositions that comprises dissolving shellac in an alkaline liquid and adding tannic acid to the resulting solution.

11. A process of making plastic compositions that comprises dissolving a varnish adhesive in a dilute solution of an alkali metal hydroxid and adding tannic acid to the resulting solution.

12. A process of making plastic compositions that consists in dissolving shellac in a dilute solution of an alkali metal hydroxid,

adding to the resulting solution suficient tannic acid to precipitate the alkali-metal as alkali-metal tannate, together with the shellac and recovering the precipitate.

13. A process of making a plastic compo sition that consists in dissolving shellac in a dilute solution of sodium hydroxid, adding to the resulting solution sufficient tannic acid to precipitate the sodium and the shellac as a mixture of sodium tannate and shellac, and recovering the precipitate.

In testimony Whereot, I have hereunto subscribed my name this 30th day of June,

JAMES P. A. MCCOY. Witnesses:

W. H. KEMPTON, B. B. HINES. 

